package cn.admin.tools;

import java.io.*;
import java.net.HttpURLConnection;
import java.net.URL;

/**
 * @Author: 毛苏宇
 * @Description: You can do it!
 * @Date: Create in 10:33 2019/4/19
 */
public class ImageUtil {
    /**
     * 根据地址获得数据的字节流
     *
     * @param strUrl 网络连接地址
     * @return
     */
    public static byte[] getImageFromNetByUrl(String strUrl) {
        try {
            URL url = new URL(strUrl);
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            conn.setRequestMethod("GET");
            conn.setConnectTimeout(5 * 1000);
            InputStream inStream = conn.getInputStream();// 通过输入流获取图片数据
            byte[] btImg = readInputStream(inStream);// 得到图片的二进制数据
            return btImg;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    /**
     * 根据地址获得数据的字节流
     *
     * @param strUrl 本地连接地址
     * @return
     */
    public static byte[] getImageFromLocalByUrl(String strUrl) {
        try {
            File imageFile = new File(strUrl);
            InputStream inStream = new FileInputStream(imageFile);
            byte[] btImg = readInputStream(inStream);// 得到图片的二进制数据
            return btImg;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    /**
     * 从输入流中获取数据
     *
     * @param inStream 输入流
     * @return
     * @throws IOException
     * @throws Exception
     */
    private static byte[] readInputStream(InputStream inStream) throws IOException {
        ByteArrayOutputStream outStream = new ByteArrayOutputStream();
        byte[] buffer = new byte[10240];
        int len = 0;
        while ((len = inStream.read(buffer)) != -1) {
            outStream.write(buffer, 0, len);
        }
        inStream.close();
        return outStream.toByteArray();

    }

    public static void main(String[] args) {
        String url = "https://images0.cnblogs.com/blog/536814/201412/051633343733092.png";
        byte[] b = getImageFromNetByUrl(url);
        System.out.println(b);
    }
}
